Fukushima reactor 1 radiation levels spike to 261,000,000 microsieverts per hour, so high it is 100% lethal in less than 2 minutes, and just short of Chernobyl reactor levels.
Lucas Whitefield Hixson tips us off to the latest radiation reading from the Fukushima nuclear reactor #1 hitting 261 sieverts per hour. For conversion purposes, that is 261,000 millisieverts per hour or 261,000,000 microsieverts per hour.